In this article available on the “Femme Actuelle” website (available in French only), Dr Stéphanie Zwillinger talks about color blindness. This anomaly of the vision affects the perception of color at the retina level. But did you know that there are several types of color blindness, and how to detect them? For more information, continue reading this article!
Introduction to color blindness
Color blindness is not a disease or a visual pathology. It is a peculiarity of the human eye that will modify the way it distinguishes colors. It is generally hereditary and recessive. Color blindness will last for life, without any evolution. It is to be noted that there is neither improvement nor deterioration.
The mechanism of the vision depends on the perception of three colors: red, blue and green. The association of these three makes it possible to form a whole nuance of colors.
To simplify the functioning of distinguishing colors:
- The retina is composed of two types of photoreceptor cells, cones and rods.
- There are 3 types of cones responsible for color vision: red cones, green cones and blue cones. The activation of these 3 receptor cones allows us to see all colors.
The cones are based on the wavelength emitted by the color. The color red has a long wavelength, the color blue a short wavelength, and the color green (medium wavelength). When one of these cones is deficient, the brain cannot receive information about the corresponding color.
This vision anomaly is identified with the help of boards representing numbers or drawings made up of colored dots on a background of another color. In this case, the affected persons will not be able to differentiate the colors and distinguish the drawing.
The COP9 team invites you to make an appointment for a more thorough ophthalmological examination, which may help determine the type of color blindness.
There are several forms of color blindness, the most common is the confusion between green and red. Read on to find out more.
The different types
There are different categories of color blindness, which are grouped into two categories, “red-green” and “blue-yellow” color blindness. According to the type, the person suffering from color blindness will consequently perceive the colors, and their environment, differently.
It is possible that a person is affected by several color blindnesses, that is to say 46 possibilities, all in different degrees. There are as many ways of seeing colors as there are people who are color blind.
The “blue-yellow” color blindness
This is the most common type of color blindness, which is thought to be the only type of color blindness. It is transmitted by the X chromosome in the mother, and it is a recessive gene. There are different types of “blue-yellow” color blindness:
- deuteranopia: total absence of the functioning of the green cones;
- protanopia: total absence of red cones function;
- deuteranomaly: a partial dysfunction of the green cones;
- protanomaly: a partial dysfunction of the red cones, which will be duller.
The “blue-yellow” color blindness
Blue-yellow color blindness is a lesser known and less common type. Nevertheless, it is just as important to detect it. This visual anomaly is unrelated to chromosomes, and there is as much chance of a man having it as a woman:
- tritanopia: total absence of blue cone function;
- tritanomaly: a partial dysfunction of the blue cones;
- achromatopsia: total absence of cone function, with monochromatic vision in shades of gray (extremely rare).
We wish to remind you that color blindness is not an eye disease, and that if you experience blurred vision, headaches or visual fatigue, do not hesitate to make an appointment with your ophthalmologist.
Symptoms of color blindness
The deficiencies are sometimes not immediately noticed by the patient. It may take many years before a person realizes that they are color blind!
Here is a list of symptoms that may alert you to the possibility that you or a loved one may have color blindness:
- difficulty in recognizing colorful characteristics of a person, such as make-up, eye color, etc;
- difficulty in differentiating between rare and cooked meat, the color of fruit..;
- a more nuanced description of colors;
- difficulty defining a color accurately.
In these cases, the alteration of the perception of the colors is accentuated with time, because of the evolution of these pathologies. If you notice that you have difficulty in differentiating tints, and a diminution of the visible spectrum of colors, it is not color blindness. Do not hesitate to consult your doctor or your ophthalmologist.
Treatments for color blindness
Patients may wonder if it is possible to cure color blindness?
Even if this anomaly cannot be prevented, its detection is very simple and is often done at the first medical visit in school.
At present, no treatment can restore normal color vision. But certain solutions are being implemented:
- professionals propose glasses allowing to compensate for the anomalies of the perception of colors;
- certain video games have already integrated filters into their settings to facilitate the immersion of color-blind players.
Despite the handicap that this can cause, the color-blind person has their own system of references to see a color. The missing shades are replaced by different shades of gray.
To conclude this article on color blindness, it is important to diagnose it as soon as possible to avoid any misunderstanding at school during learning and to put in place solutions and aids to avoid penalizing the child. Visual acuity is not affected by this anomaly and does not lead to any vision problems. In short, color blind people see things differently!